Incontinence devices are known and have included such implanted devices that contract the urethra to prevent urinary leakage or that contract the bowel to prevent fecal leakage. Similarly, the esophagus may be contracted to prevent gastro-esophageal reflux (GER). These devices are commonly referred to as “artificial sphincters” and are installed within the body to aid or replace the body's natural sphincter.
One such type of artificial urinary sphincter is described in U.S. Pat. Nos. 5,704,893 & 6,074,341 both entitled “Vessel Occlusive Apparatus and Method.” A device of this type was entered into human clinical trials by Timm Medical Technologies, Inc. However, its proper function was impeded by growth of a constricting tissue capsule around its mechanisms, due to the natural defenses of the human body. The human body ordinarily exhibits a defense mechanism by causing a tissue capsule to form around the synthetic structures of man-made implantable devices in an attempt to wall it off from the rest of the body.
Attempts have been made to minimize tissue capsule growth around medical devices by impregnating them with various drugs intended to interrupt cellular processes causing capsular formation. Several examples have included using the drug Sirolimus (Rapamycin) are described in U.S. Pat. No. 6,534,693 “Surgically Implanted Devices Having Reduced Scar Tissue Formation.” Sirolimus is also currently being used in intravascular coronary stents to prevent restenosis of coronary arteries, which typically accompanies coronary angioplasty and coronary artery stenting.
Further, the anti-inflammatory drug dexamethasone has a long history in the reduction of inflammatory response and subsequent capsular formation around implanted devices. For example, it is used in Medtronic, Inc. (Minneapolis, Minn.) Intra Coronary Defibrillation (ICD) leads and Endotak Reliance® Tined Endocardial Defibrillation ICD leads produced by Guidant Corporation (St. Paul, Minn.). The drug is intended to prevent formation of tissue capsules with high electrical impedance around the electrode. Abbott Laboratories, Inc. (Redwood City, Calif.) has entered its BiodivYsio dexamethasone-eluting intracoronary stent into clinical trials and demonstrated its ability to minimize coronary restenosis.
While it appears that such drugs have largely been employed in stenting and coronary implant procedures, advancements may yet be made to employing these principles in other applications, such as in implantable incontinence devices.